Abstract <p>We mapped the evidence on the use of respiratory oscillometry (RO) in infants through a scoping review of the literature. We conducted a systematic search of Medline, Embase, Cochrane Library, Web of Science, Google Scholar, Cochrane Controlled Register of Trials, and clinical trial registries from inception to 1st September 2025. We included documents on the use of RO in infants up to 1 year. We assessed risk of bias using the Risk of Bias In Non-randomised studies of Interventions (ROBINS-I) and the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). Reporting adheres to the PRISMA extension for Scoping Reviews. We included 45 papers and 7 protocols. Five themes emerged: feasibility and methodology; RO for assessing pathological conditions and exposures; prognostication of respiratory outcomes; ability to evaluate treatment response in the neonatal intensive care (NICU); role in bronchodilator/bronchoconstrictor testing in infants with wheezing. RO was feasible and may be a reliable modality for epidemiological studies of early lung function determinants and long-term follow-up of infants. It may also support individualised respiratory care in the NICU, although it has been used primarily as a research tool in this setting. Wider adoption requires infant-specific devices, standardised methodologies, and reference values.</p> Impact <p><UnorderedList Mark="Bullet"> <ItemContent> <p>This is the first comprehensive scoping review mapping the evidence on respiratory oscillometry in neonates and infants under one year of age.</p> </ItemContent> <ItemContent> <p>Respiratory oscillometry may be a reliable modality for long-term monitoring of lung function starting in infancy.</p> </ItemContent> <ItemContent> <p>Respiratory oscillometry may support individualised respiratory care and prognostication in the neonatal intensive care unit.</p> </ItemContent> </UnorderedList></p>